Adapter assembly and loading units for surgical stapling devices

ABSTRACT

A surgical apparatus is provided. The surgical apparatus includes a proximal body portion, a distal body portion selectively articulable relative to the proximal body portion at an articulation joint, and a first drive gear disposed within the distal body portion. The distal body portion has a diameter and a length. The length of the distal body portion is substantially the same as the diameter of the distal body portion.

BACKGROUND

1. Technical Field

The present disclosure relates to surgical stapling devices. Morespecifically, the present disclosure relates to adapter assemblies foruse with the powered surgical stapling devices and loading units for usewith the adapter assemblies.

2. Background of Related Art

Surgical stapling devices having a powered handle are known. Suchdevices typically include an adapter assembly for connecting loadingunits to the powered handle. Often the adapter assemblies transferrotational motion from one or more motors in the powered handle assemblyinto linear motion to actuate and articulate the attached loading units.Because replacing a used disposable loading unit or replacing a usedcartridge assembly of a multiple use loading unit during a surgicalprocedure may be a complicated and/or time consuming process, it wouldbe desirable to have an adapter assembly and loading unit with an easilyattachable and replaceable loading unit.

SUMMARY

Accordingly, a surgical apparatus is provided. The surgical apparatusincludes a proximal body portion a distal body portion selectivelyarticulable relative to the proximal body portion at an articulationjoint and including a distal end configured for selective engagementwith a loading unit, and a first drive gear disposed within the distalbody portion. The distal body portion defines a longitudinal axis andhaving a diameter and a length. The length of the distal body portion issubstantially the same as the diameter of the distal body portion. Thedrive gear may be rotatable about the longitudinal axis. The surgicalapparatus may further include a handle assembly. A proximal end of theproximal body portion may be connected to the handle assembly.

In embodiments, the surgical apparatus further includes a loading unitselectively engageable with the distal end of the distal body portion.The loading unit may include a second drive gear configured to engagethe first drive gear when the loading unit is secured to the distal endof the distal body portion. The loading unit may include a drive screwand the second drive gear may be disposed on a proximal end of the drivescrew. The loading unit may include a drive beam operably disposed onthe drive screw. Rotation of the drive screw may cause advancement ofthe drive beam to staple and cut tissue.

In some embodiments, the surgical apparatus includes a rotation geardisposed within the distal body portion for rotating the distal end ofthe distal body portion about the longitudinal axis. The surgicalapparatus may further include a drive transfer assembly extendingbetween the proximal and distal body portions. The drive transferassembly may include first and second horizontal bevel gears disposedabout the articulation joint. A first distal bevel gear may be operablyconnected to the first horizontal bevel gear and a second distal bevelgear may be operably connected the second bevel gear. The first distalbevel gear may be connected to the first drive gear by a first spur gearand the second distal bevel gear may be connected to the rotation gearby a second spur gear. The first and second spur gears, the rotationgear, and the drive gear may be disposed within the same cross-sectionalplane. The drive transfer assembly may further includes a first proximalbevel gear operably connected to the first horizontal bevel gear and asecond proximal bevel gear operably connected to the second horizontalbevel gear.

The surgical apparatus may further include first and second drive shaftsextending through the proximal body portion. The first drive shaft maybe operably connected to the first proximal bevel gear and the seconddrive shaft may be operably connected to the second proximal bevel gear.The surgical apparatus may further include an articulation assemblydisposed within the proximal body portion and a pivot member disposedwithin the articulation joint. The pivot member may be fixedly securedto the distal body portion and pivotally secured to the proximal bodyportion. The articulation assembly may include a flexible band receivedabout the pivot member. The flexible band may be operably connected to athird drive shaft extending through the proximal body portion. Rotationof the third drive shaft may effectuate articulation of the distal bodyportion relative to the proximal body portion.

An adapter assembly for connecting a loading unit to a handle assemblyis provided is also provided. The adapter assembly includes a proximalbody portion defining a longitudinal axis, a distal body portionselectively articulable relative to the proximal body portion, and anarticulation assembly for articulating the distal body portion relativeto the proximal body portion. The articulation assembly includes a pivotmember fixedly secured to the distal body portion and rotatably securedrelative to the proximal body portion and a flexible band received aboutthe pivot member and including first and second ends, whereinlongitudinal translation of the first and second ends of the flexibleband causes articulation of the distal body portion relative to theproximal body portion. The proximal body portion may be configured foroperable engagement with a handle assembly and the distal body portionmay be configured for operable engagement with a loading unit.

In embodiments, the articulation assembly may further include aconnector tube secured to the flexible band and a drive screw inoperable engagement with the connector tube. Rotation of the drive screwrelative to the connector tube may cause longitudinal translation of thefirst and second ends of the flexible band. Rotation of the drive screwin a first direction may translate the first end of the flexible band ina first longitudinal direction to articulate the distal body portion ina first direction relative to the proximal body portion. In addition,rotation of the drive screw in a second direction may translate thefirst end of the flexible band in a second longitudinal direction toarticulate the distal body portion in a second direction. A proximal endof the drive screw may be configured for operable connection with adrive shaft of a handle assembly.

In some embodiments, the articulation assembly includes a tensioningmechanism for maintaining the flexible band in tension about the pivotmember. The tensioning mechanism may operably engage proximal and distalportion of the flexible band to maintain the flexible band in tensionabout the pivot member. The tensioning mechanism may include atensioning housing, a tensioning screw, and a tensioning gear rotatablyreceived within the tensioning housing, the tensioning gear operablyengaging the proximal and distal portions of the flexible band tomaintain the flexible band in tension about the pivot member. Rotationof the tensioning screw relative to the tensioning housing in a firstdirection may increase the tension of the flexible band on the pivotmember and rotation of the tensioning screw relative to the tensioninghousing in a second direction may reduce the tension of the flexibleband on the pivot member. The tensioning gear may operably engage theproximal and distal portions of the flexible band to move the proximaland distal portions of the flexible band relative to each other duringlongitudinal translation of the flexible band.

The adapter assembly may further including a drive assembly extendingtherethough for actuating a loading unit when the loading unit issecured to distal body portion. The adapter assembly may include a latchmechanism operably received within distal body portion for selectivelysecuring the loading unit to the distal body portion. The loading unitmay include a cartridge assembly, an anvil assembly pivotally securedrelative to the cartridge assembly between an open position and a closedposition, and a plunger assembly for biasing the anvil assembly to theopen position.

In addition, an adapter assembly for connecting a loading unit to ahandle assembly is also provided. The adapter assembly includes aproximal body portion defining a longitudinal axis, a distal bodyportion selectively articulable relative to the proximal body portion,and an articulation assembly for moving the distal body portion relativeto the proximal body portion. The articulation assembly includes aflexible band for moving the distal body portion relative to theproximal body portion. A first end of the flexible band is operablyconnected to a drive screw for effecting longitudinal movement of theflexible band.

The adapter assembly may further include a pivot member received betweenthe proximal body portion and the distal body portion, the pivot memberbeing fixed to the distal body portion and movable relative to theproximal body portion. The flexible band may be received about the pivotmember to effect movement of the distal body portion relative to theproximal body portion. A tensioning mechanism may be received betweenfirst and second ends of the flexible member to move the second end ofthe flexible band relative to the first end of the flexible band.

Also provided is a surgical stapler including a handle assembly, anelongated body extending from the handle assembly, and a loading unitselectively secured to the elongated body. The loading unit includes acartridge assembly, an anvil assembly pivotally secured relative to thecartridge assembly between an open position and a closed position, and aplunger assembly for biasing the anvil assembly to the open position,wherein the plunger assembly extends parallel to a longitudinal axis ofthe loading unit. The plunger assembly may include a plunger configuredto engage a flange formed on a proximal end of the anvil assembly. Theplunger may be biased distally by a spring.

Further, a surgical stapler including an adapter assembly and a loadingunit is provided. The adapter assembly includes a body portion includinga tongue and defining a longitudinal opening. The adapter assemblyfurther includes a latch mechanism operably received within thelongitudinal opening. The latch mechanism includes a latch member and aspring for biasing the latch mechanism in a distal direction. Theloading unit is selectively securable to the adapter assembly anddefines a cutout for selectively receiving the tongue and a recess forselectively receiving a distal end of the latch member for selectivelysecuring the loading unit to the adapter assembly.

In embodiments, the loading unit may include an extension defining thecutout and the recess. The latch member may include a proximal portionconfigured for operable engagement by a user to bias the latch member ina proximal direction. The body portion may include a pair of inwardlyextending lips and the extension may define a pair of notches forselectively receiving the respective pair of inwardly extending lips.The distal end of the latch member may be conical. The biasing membermay be a compression spring received about a proximal end of the latchmember.

The loading unit may further include a locking mechanism for locking theloading unit to the adapter assembly. The locking mechanism may includeat least one locking member and the distal body portion of the adapterassembly may define at least one longitudinal bore. A proximal end ofthe at least one locking member may be selectively receivable within theat least one longitudinal bore to secure the loading unit to the adapterassembly.

The surgical stapler may further include a cartridge assemblyselectively engageable to the loading unit, wherein the proximal end ofthe at least one locking member is received within the at least onelongitudinal bore when the cartridge assembly is engaged with theloading unit to secure the loading unit to the adapter assembly. Theproximal end of the at least one locking member may be retracted fromwithin the at least one longitudinal bore when the cartridge assembly isseparated from the loading unit to permit separation of the loading unitfrom the adapter assembly. The loading unit may include a carrierdefining a longitudinal recess for receiving the cartridge assembly. Theat least one locking member may include a distal end slidably disposedwithin the longitudinal recess engageable by the cartridge assembly whenthe cartridge assembly is received within the longitudinal recess.Engagement of the cartridge assembly with the distal end of the at leastone locking member may move the proximal end of the at least one lockingmember into the at least one longitudinal bore to secure the loadingunit to the adapter assembly.

Also provided is a method of securing a loading unit to an adapterassembly. The method includes aligning a tongue formed on a distal endof an adapter assembly with a cutout formed on a proximal end of aloading unit and receiving the tongue of the adapter assembly within thecutout of the loading unit until a latch member of the adapter assemblyis biased within a recess of the loading unit.

In embodiments, aligning the tongue of the adapter assembly with thecutout of the loading unit further includes aligning a pair of inwardlyextending lips of the adapter assembly with a pair of notches of theloading unit. Receiving the tongue of the adapter assembly within thecutout of the loading unit further includes receiving the pair ofinwardly extending lips of the adapter assembly within the respectivepair of notches of the loading unit. The method may further includereceiving a cartridge assembly within the loading unit to actuate alocking mechanism to secure the loading unit to the adapter assembly.Receiving the cartridge assembly within the loading unit may includeengaging a locking member of the locking mechanism with the cartridgeassembly to move the locking member into engagement with the adapterassembly.

In addition, an adapter assembly for a surgical stapler is provided. Theadapter assembly includes a proximal body portion and a distal bodyportion selectively articulable relative to the proximal body portionabout an articulation joint. The distal body portion having a diameterand a length. The adapter assembly further includes a drive geardisposed within the distal body portion for rotating a lead screw of aloading unit attached to the distal body portion. The length of thedistal body portion is substantially the same as the diameter of thedistal body portion.

In embodiments, the adapter assembly further includes a rotation geardisposed within the distal body portion for rotating a distal housing ofthe distal body portion about a longitudinal axis of the distal bodyportion. The adapter assembly may further include a drive transferassembly extending between the proximal and distal body portions. Thedrive transfer assembly may include first and second horizontal bevelgears disposed within the articulation joint, a first distal bevel gearoperably connected to the first horizontal bevel gear, and a seconddistal bevel gear operably connected the second bevel gear. The firstdistal bevel gear may be connected to the drive gear by a first spurgear and the second distal bevel gear may be connected to the rotationgear by a second spur gear. The first and second spur gears, therotation gear, and the drive gear may be disposed within the samecross-sectional plane. The drive transfer assembly may further include afirst proximal bevel gear operably connected to the first horizontalbevel gear and a second proximal bevel gear operably connected to thesecond horizontal bevel gear.

The adapter assembly may include first and second drive shafts extendingthrough the proximal body portion. The first drive shaft may be operablyconnected to the first proximal bevel gear and the second drive shaftmay be operably connected to the second proximal bevel gear. The adapterassembly may further include an articulation assembly disposed withinthe proximal body portion. The articulation assembly may include aflexible band received about the articulation joint. A proximal end ofthe proximal body portion is configured for operable connection to ahandle assembly and a distal end of the distal body portion isconfigured for operable connection with a loading unit.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure are described herein withreference to the accompanying drawings, wherein:

FIG. 1 is a perspective view of an electromechanical surgical staplingdevice including an adapter assembly, loading unit and cartridgeassembly, in accordance with an embodiment of the present disclosure,and a powered handle assembly;

FIG. 2 is a perspective view of the powered handle assembly shown inFIG. 1;

FIG. 3 is a perspective side view of the adapter assembly shown in FIG.1;

FIG. 4 is a cross-sectional side view of the adapter assembly and theloading unit shown in FIG. 1;

FIG. 5 is an enlarged view of the indicated area of detail shown in FIG.4;

FIG. 6 is a cross-sectional top view of the adapter assembly, theloading unit, and cartridge assembly shown in FIG. 1;

FIG. 7 is an enlarged view of the indicated area of detail shown in FIG.6;

FIG. 8 is a perspective end view of the adapter assembly shown in FIG. 1with an outer sleeve removed and a proximal end shown in phantom;

FIG. 9 is an enlarged view of the indicated area of detail shown in FIG.8;

FIG. 10 is an exploded perspective view of a proximal body portion ofthe adapter assembly shown in FIG. 1;

FIG. 11 is an exploded perspective view of an articulation assembly ofthe adapter assembly shown in FIG. 1;

FIG. 12 is a cross-sectional top view of a distal end of the adapterassembly and the loading unit shown in FIG. 1;

FIG. 13 is a perspective top view of the distal end of the adapterassembly and a proximal end of the loading unit shown in FIG. 1, withconnector housings and the outer sleeve of the adapter assembly shown inphantom;

FIG. 14 is a perspective side view of the articulation assembly shown inFIG. 11;

FIG. 15 is an exploded perspective view of a distal body portion of theadapter assembly shown in FIG. 1;

FIG. 16 is an enlarged perspective view of the distal end of the adapterassembly and an actuation assembly of the loading unit shown in FIG. 1,with housings shown in phantom;

FIG. 17 is an enlarged perspective view of the distal end of the adapterassembly shown in FIG. 1 with the housings shown in phantom;

FIG. 18 is a cross-sectional end view taken along line 18-18 in FIG. 16;

FIG. 19 is a perspective side view of the loading unit and the cartridgeassembly shown in FIG. 1;

FIG. 20 is an exploded perspective view of the loading unit shown inFIG. 1;

FIG. 21 is an enlarge perspective side view of the distal end of theadapter assembly and the proximal end of the loading unit shown in FIG.1, as the loading unit is secured to the adapter assembly;

FIG. 22 is a perspective side view of the distal end of the adapterassembly and the proximal end of the loading unit shown in FIG. 21, withthe loading unit secured to the adapter assembly;

FIG. 23 is an enlarged view of the indicated area of detail shown inFIG. 4;

FIG. 24 is a perspective side view of a drive beam of the loading unitshown in FIG. 1;

FIG. 25 is a cross-sectional side view of the drive beam shown in FIG.24;

FIG. 26 is a cross-sectional perspective end view of the drive beamshown in FIG. 24;

FIG. 27 is a perspective side view of the distal end of the adapterassembly and a proximal end of the actuation assembly shown in FIG. 16,further including a locking mechanism in a first or distal position;

FIG. 28 is a perspective view of the distal end of the adapter assembly,the proximal end of the actuation assembly, and the locking mechanismshown in FIG. 27, further including a proximal end of the cartridgeassembly shown in FIG. 1, with the locking mechanism in the second orproximal position;

FIG. 29 is an enlarged view of the indicated area of detail shown inFIG. 12;

FIG. 30 is a perspective end view of the cartridge assembly shown inFIG. 1;

FIG. 31 is an enlarged view of the indicated area of detail shown inFIG. 30;

FIG. 32 is a perspective side view of an alternative embodiment of adistal end of an adapter assembly and loading unit according to thepresent disclosure;

FIG. 33 is an exploded perspective side view of the proximal end of theadapter assembly shown in FIG. 32;

FIG. 34 is a perspective side view of the loading unit shown in FIG. 32;

FIG. 35A is a perspective end view of a plunger member of the loadingunit shown in FIG. 32,

FIG. 35B is another perspective end view of the plunger member shown inFIG. 35A;

FIG. 36 is a cross-sectional top view of the loading unit shown in FIG.32;

FIG. 37 is an enlarged view of the indicated area of detail shown inFIG. 32 with the anvil assembly in a closed position;

FIG. 38 is an enlarged view of the indicated area of detail shown inFIG. 36, with the anvil assembly in the closed position;

FIG. 39 is an enlarged view of the indicated area of detail shown inFIG. 32 with the anvil assembly in an opened position; and

FIG. 40 is an enlarged view of the indicated area of detail shown inFIG. 36, with the anvil assembly in the opened position.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the presently disclosed adapter assembly and loadingunits for surgical devices and/or handle assemblies are described indetail with reference to the drawings, in which like reference numeralsdesignate identical or corresponding elements in each of the severalviews. As used herein the term “distal” refers to that portion of theadapter assembly or surgical device, or component thereof, farther fromthe user, while the term “proximal” refers to that portion of theadapter assembly or surgical device, or component thereof, closer to theuser.

With reference to FIG. 1, an adapter assembly in accordance with anembodiment of the present disclosure, shown generally as adapterassembly 100, and a loading unit according to an embodiment of thepresent disclosure, shown generally as loading unit 200, are configuredfor selective connection to a powered hand-held electromechanicalinstrument, shown generally as handle assembly 10. The adapter assembly100 is configured for selective connection with the handle assembly 10,and, the loading unit 200 is configured for selective connection withthe adapter assembly 100. As will be shown and described in detailbelow, the loading unit 200 is a multiple use loading unit (“MULU”)configured to selectively receive a replaceable loading unit, i.e.,cartridge assembly 300. The adapter assembly 100, the loading unit 200and the cartridge assembly 300 operate to staple and cut tissue.Although shown and described as being formed independent of the handleassembly 10, it is envisioned that the aspects of the adapter assembly100 may be directly incorporated into the handle assembly 10.

As illustrated in FIGS. 1 and 2, the handle assembly 10 includes ahandle housing 12 having a lower housing portion 14, an intermediatehousing portion 16 extending from and/or supported on the lower housingportion 14, and an upper housing portion 18 extending from and/orsupported on the intermediate housing portion 16. A distal half-sectionof the upper housing portion 18 defines a nose or connecting portion 18a configured to accept a corresponding drive coupling assembly 110 ofthe adapter assembly 100. For a detailed description of the structureand function of an exemplary powered hand-held electromechanicalinstrument, please refer to commonly owned U.S. Pat. Appl. Publ. No.2012/0253329 (“the '329 application”) and U.S. Pat. Appl. Publ. No.2012/0323226 (“the '226 application), the contents of which areincorporated by reference herein in their entirety.

The adapter assembly 100 will now be described with reference to FIGS.3-18. Referring initially to FIG. 3, the adapter assembly 100 includes aproximal body portion 102 and a distal body portion 104. The proximalbody portion 102 includes a proximal end 102 a configured for operableconnection to the connecting portion 18 a (FIG. 2) of the handleassembly 10 (FIG. 2) and a distal end 102 b pivotally connected to aproximal end 104 a of the distal body portion 104 at an articulationjoint 105 (FIG. 3). More particularly, and as will be described infurther detail below, a first connector housing 106 is disposed on thedistal end 102 b of the proximal body portion 102 and is pivotallysecured to a distal connector housing 108 disposed on the proximal end104 a of the distal body portion 104 at the articulation joint 105 by apivot pin 107. The distal body portion 104 includes a distal end 104 bconfigured for selective connection to the loading unit 200 (FIG. 1). Aswill also be described in further detail below, the compact length ofthe distal body portion 104 allows for greater manipulation of anattached loading unit 200 within a body cavity (not shown) during asurgical procedure. The ability of the distal body portion 104 to pivotthrough an arc of one-hundred eight degrees (180°) relative to theproximal body portion 102 allows for further manipulation of an attachedloading unit 200.

The proximal body portion 102 of the adapter assembly 100 includes thedrive coupling assembly 110 (FIG. 5) and an articulation assembly 130(FIG. 12) operably connected to the drive coupling assembly 110 andmaintained within an outer sleeve 103 of the proximal body portion 102.A drive transfer assembly 160 (FIG. 15) extends between the proximal anddistal body portions 102, 104 of the adapter assembly 100 and operablyconnects the drive coupling assembly 110 to a drive assembly 190 (FIG.15) disposed within the distal body portion 104 of the adapter assembly100.

With reference to FIGS. 4-10, as shown, the drive coupling assembly 110has a cylindrical profile and is configured to selectively secure theadapter assembly 100 to the handle assembly 10 (FIG. 1). The drivecoupling assembly 110 includes a connector housing 112 and a connectorextension 114 fixedly connected to the connector housing 112 by anannular ring 113. The annular ring 113 may include a groove 113 a orother feature for securing the adapter assembly 100 to the handleassembly 10. The connector extension 114 may include a notch 114 a orother feature formed in an outer surface thereof for facilitatingalignment of the adapter assembly 100 with the connector portion 18 a ofthe handle assembly 10.

The connector housing 112 and the connector extension 114 operate torotatably support a first drive shaft 116 (FIG. 5), a second drive shaft118 (FIG. 7), and a third drive shaft 120 (FIG. 5). The connectorhousing 112 and the connector extension 114 of the drive couplingassembly 110 also rotatably support the first, second, and thirdconnector sleeves 122 (FIG. 5), 124 (FIG. 7), and 126 (FIG. 5),respectively. The first, second, and third connector sleeves 122, 124,and 126 are configured to mate with the respective first, second, andthird drive connectors (not shown) of the handle assembly 10 (FIG. 1)and are further configured to mate with a proximal end 116 a, 118 a, 120a of the respective first, second, and third drive shafts 116 (FIG. 5),118 (FIG. 7), and 120 (FIG. 5) of the adapter assembly 100.

The drive coupling assembly 110 also includes first, second and thirdbiasing members 122 a (FIG. 5), 124 a (FIG. 7), and 126 a (FIG. 5)disposed distally of the respective first, second, and third connectorsleeves 122, 124, and 126. The first, second, and third biasing members122 a, 124 a, 126 a are disposed about the respective first, second, andthird drive shafts 116, 118, and 120 to facilitate engagement of therespective first, second, and third connector sleeves 122, 124, and 126with respective first, second, and third rotatable drive connectors (notshown) of the handle assembly 10 (FIG. 1) when the adapter assembly 100is connected to the handle assembly 10. In particular, the first,second, and third biasing members 122 a, 124 a, and 126 a function tobias the respective first, second, and third connector sleeves 122, 124,and 126 in a proximal direction. First, second, and third washers 122 b,124 b, and 126 b are received about the respective proximal ends 116 a,118 a, and 120 a of the respective first, second, and third drive shafts116, 118, and 120 to maintain the respective first, second, and thirdbiasing members 122 a, 124 a, and 126 a relative to the respectivefirst, second, and third drive shafts 116, 118, and 120. A spring clip124 c (FIG. 7) is received about the second drive shaft 118 adjacent theproximal end 118 a of the second drive shaft 118 to secure the seconddrive shaft 118 relative to the connector housing 112 of the drivecoupling assembly 110.

For a detailed description of an exemplary drive coupling assembly,reference may be made to the '329 application, the content of which waspreviously incorporated by reference herein.

With reference now to FIGS. 10-16, the articulation assembly 130 effectsarticulation of the distal body portion 104 (FIG. 3) of the adapterassembly 100 relative to the proximal body portion 102 (FIG. 3) of theadapter assembly 100. With particular reference to FIGS. 10 and 11, thearticulation assembly 130 includes an articulation housing 132 and asupport plate 134 secured to a proximal end of the articulation housing132 by a pair of screws 131. A connector tube 136 extends through anopening 135 a in the support plate 134 and includes a threaded innersurface 137 for receiving a threaded connector screw 138. A proximal end136 a of the connector tube 136 operably engages an adapter member 118 cthat is secured to the distal end 118 b (FIG. 10) of the second driveshaft 118.

The articulation assembly 130 further includes a flexible band 140slidably disposed relative to the articulation housing 132. A first end140 a of the flexible band 140 is secured to the connector screw 138 bya first connector 142 and a second end 140 b of the flexible band 140 issecured to a second connector 144. More particularly, the first andsecond connectors 142, 144 are each secured to the flexible band 140 byfirst and second adaptors 146 a, 146 b which are fixedly secured to thefirst and second ends 140 a, 140 b, respectively, of the flexible band140 and operably secured to the respective first and second connectors142, 144. The first and second adaptors 146 a, 146 b may be secured tothe flexible band 140 by adhesive, welding, mechanical fasteners, or inany other suitable manner. Alternatively, the first and secondconnectors 142, 144 are directly secured to the flexible band 140without the use of the first and second adaptors 146 a, 146 b. Each ofthe first and second connectors 142, 144 may be in the form of a gearrack each including a toothed surface 142 a, 144 a for operableengagement with a tensioning mechanism 148.

Turning briefly to FIG. 15, the flexible band 140 is received about apivot member 150. The pivot member 150 is secured between the proximalconnector housing 106 of the proximal body portion 102 and the distalconnector housing 108 of the distal body portion 104 by the pivot pin107. The pivot member 150 is pivotal relative to the proximal connectorhousing 106 and is fixedly secured to the distal connector housing 108.Rotation of the pivot member 150 about the pivot pin 107 throughoperation of the articulation assembly 130, i.e., longitudinal movementof the flexible band 140 relative to the pivot member 150, causesarticulation of the distal body portion 104 of the adapter assembly 100relative to the proximal body portion 102 of the adapter assembly 100.

During use, the articulation assembly 130 is actuated through rotationof the second drive shaft 118. In particular, rotation of the seconddrive shaft 118 causes rotation of the connector tube 136. Rotation ofthe connector tube 136 causes longitudinally movement of the connectorscrew 138. When the connector tube 136 is rotated in a first direction,the connector screw 138 is moved longitudinally in a proximal directionand when the connector tube 136 is rotated in a second direction(opposite the first direction), the connector screw 138 is moved in adistal direction. As noted above, the connector screw 138 is connectedto the first connector 142 and the first connector 142 is connected tothe flexible band 140. Thus, longitudinal movement of the firstconnector 142 causes corresponding movement of the flexible band 140.Since the flexible band 140 is received or fixedly connected about thepivot member 150, longitudinal movement of the flexible band 140 causescorresponding pivoting of the pivot member 150.

With continued reference to FIGS. 10-14, the flexible band 140 ismaintained in tension about the pivot member 146 by the tensioningmechanism 148 received between the first and second connectors 142, 144of the articulation assembly 130. The tensioning mechanism 148 includesa tensioning housing 152, a tensioning screw 154, a biasing member 156,and a tensioning gear 158 rotatably received within the tensioninghousing 152 by a pivot pin 153. The tensioning housing 152 is adjustablysecured to the tensioning screw 154 such that the tensioning housing 152is slidably disposed within the articulation housing 132 between thefirst and second connectors 142, 144. The biasing member 156 is receivedabout the tensioning screw 154 and engages the articulation housing 132.The biasing member 156 applies a force on the tensioning screw 154 whichpulls the tensioning housing 152 in a proximal direction. The forceapplied by the biasing member 156 on the tensioning screw 154 can beadjusted by rotating the tensioning screw 154 and acts on the first andsecond connectors 142, 144 through the tensioning gear 158 to keep thefirst and second connectors 142, 144 and the flexible band 140 intension, thereby ensuring that the first and second connectors 142, 144move uniformly during operation of the articulation assembly 130. Inthis manner, the tensioning mechanism 148 ensures that the firstconnector 142 is advanced or retracted at the same rate as the secondconnector 144 is retracted or advanced. The tensioning mechanism 148 mayalso operate to maintain frictional engagement between the flexible band140 and the pivot member 150. Alternatively, the flexible band 140 issecured to the pivot member 150 using an adhesive, mechanical fasteneror other in any other suitable manner.

With particular reference again to FIG. 15 and additional reference toFIGS. 16-18, the drive transfer assembly 160 operably connects the drivecoupling assembly 110 (FIG. 10) with the drive assembly 190. The drivetransfer assembly 160 includes first and second proximal bevel gears162, 164, first and second horizontal bevel gears 166, 168, and firstand second distal bevel gears 170, 172. The first proximal bevel gear162 is rotatably supported within the proximal connector housing 106 bya first bearing assembly 163. A first end 162 a of the first proximalbevel gear 162 operably engages the distal end 116 b (FIG. 10) of thefirst drive shaft 116 of the drive coupling assembly 110 and a secondend 162 b of the first proximal bevel gear 162 engages the firsthorizontal bevel gear 166. The second proximal bevel gear 164 isrotatably supported within the proximal connector housing 106 by asecond bearing assembly 165. A first end 164 a of the second proximalbevel gear 164 operably engages the distal end 120 b (FIG. 10) of thethird drive shaft 120 of the drive coupling assembly 110 and a secondend 164 b of the second proximal bevel gear 164 engages the secondhorizontal bevel gear 168.

The first and second horizontal bevel gears 166, 168 are rotatablysupported within the pivot member 150 of the articulation assembly 130(FIG. 10) about the pivot pin 107. The first horizontal bevel gear 166operably engages a first end 170 a of the first distal bevel gear 170and the second horizontal bevel gear 168 operably engages a first end172 a of the second distal bevel gear 170. The first and second distalbevel gears 170, 172 are rotatably supported within the distal connectorhousing 108. A second end 170 b of the first distal bevel gear 170includes or supports a first spur gear 174 and a second end 172 b of thesecond distal bevel gear 172 includes or supports a second spur gear176. In this manner, power transmission between the proximal and distalbody portions 102, 104 occurs within the articulation joint 105.

The drive transfer assembly 160 operates to transfer the rotationalmotion from the first and third drive shafts 116, 120 (FIG. 10) of thedrive coupling assembly 110 in the proximal body portion 102 of theadapter assembly 100 to rotational motion of the respective first andsecond spur gears 174, 176 within the distal body portion 104 of theadapter assembly 100. As will be described in further detail below,rotation of the first spur gear 174 causes actuation of the loading unit200 (FIG. 1) and rotation of the second spur gear 176 causes rotation ofthe loading unit 200 (FIG. 1) about the longitudinal axis “x” of theadapter assembly 100.

With particular reference to FIG. 16, the first drive shaft 116 (FIG.10) rotates the first proximal bevel gear 162 in a first direction abouta first longitudinal axis (not shown) extending parallel to thelongitudinal axis “x” of the adapter assembly 100. Engagement betweenthe first proximal bevel gear 162 and the first horizontal bevel gear166 causes the first horizontal bevel gear 166 to rotate about alongitudinal axis (not shown) of the pivot pin 107, i.e., perpendicularto the longitudinal axis “x” of the adapter assembly 100. Engagementbetween the first horizontal bevel gear 166 and the first distal bevelgear 170 causes rotation of the first spur gear 174 in a seconddirection about the first longitudinal axis (not shown) of the adapterassembly 100 when the proximal and distal body portions 102, 104 (FIG.3) of the adapter assembly 100 are axially aligned. The drive transferassembly 160 permits the transfer of rotational motion from the firstdrive shaft 116 to the first spur gear 174 throughout articulation ofthe distal body portion 104 of the adapter assembly 100 relative to theproximal body portion 102 of the adapter assembly 100.

With particular reference to FIG. 17, the third drive shaft 120 (FIG.10) rotates the second proximal bevel gear 164 in a first directionabout a second longitudinal axis (not shown) extending parallel to thelongitudinal axis “x” of the adapter assembly 100. Engagement betweenthe second proximal bevel gear 164 and the second horizontal bevel gear168 causes the second horizontal bevel gear 168 to rotate about thelongitudinal axis (not shown) of the pivot pin 107, i.e., perpendicularto the longitudinal axis “x” of the adapter assembly 100. Engagementbetween the second horizontal bevel gear 168 and the second distal bevelgear 172 causes rotation of the second spur gear 176 in a seconddirection about the second longitudinal axis (not shown) of the adapterassembly 100 when the proximal and distal body portions 102, 104 of theadapter assembly 100 are axially aligned. The drive transfer assembly160 permits the transfer of rotational motion from the third drive shaft120 to the second distal spur gear 176 throughout articulation of thedistal body portion 104 of the adapter assembly 100 relative to theproximal body portion 102 of the adapter assembly 100.

With continued reference to FIGS. 15-17, the distal body portion 104 ofthe adapter assembly 100 includes a cylindrical housing 182 rotatablysupported relative to the distal connector housing 108, a support plate184 securely supported on or connected to the distal connector housing108, and a latch housing 186 securely supported to the cylindricalhousing 182. The cylindrical housing 182 includes a toothed innersurface 182 a for effecting rotation of the cylindrical housing 182 andthe latch housing 186. Although shown secured to the distal connectorhousing 108 by a pair of screws 183, the support plate 184 may besecured to the distal connector housing 108 in any suitable manner.

The latch housing 186 of the distal body portion 104 of the adapterassembly 100 is configured for selective connection with the loadingunit 200. More particularly, the latch housing 186 includes a tongue 186a and a pair of inwardly extending lips 186 b. As will be described infurther detail below, the tongue 186 a and the lips 186 b cooperate toengage the loading unit 200. The latch housing 186 defines a firstlongitudinal opening 185 a for receiving a pivot pin 187 and a secondlongitudinal opening 185 b for operably receiving a latch member 188 anda biasing member 189. Biasing member 189 may include a compressionspring, as shown in FIG. 15, or any other means capable of biasing thelatch member 188 in a distal direction. As will be described in furtherdetail below, the latch housing 186 further includes a pair of bores 185c for receiving a pair of locking members 252 that selectively extendfrom the loading unit 200 to prevent separation of the loading unit 200from the adapter assembly 100 when the cartridge assembly 300 isreceived within the loading unit 200.

The distal body portion 104 of the adapter assembly 100 operablysupports the drive assembly 190 of the adapter assembly 100. The driveassembly 190 includes a drive gear assembly 192 rotatably received aboutthe pivot pin 187. The drive gear assembly 192 includes a primary drivegear 192 a and a secondary drive gear 192 b fixedly secured relative tothe primary drive gear 192 a such that the secondary drive gear 192 brotates as the primary drive gear 192 a is rotated. The drive gearassembly 190 further includes a rotation drive gear 194 for causingrotation of the cylindrical housing 182 and the latch housing 186relative to the distal connector housing 108 of the distal body portion104. When the loading unit 200 is secured to the latch housing 182,rotation of the drive gear 194 causes rotation of the loading unit 200.

As shown in FIG. 18, the primary drive gear 192 a of the drive gearassembly 192 engages the first spur gear 174 mounted on the second end170 b of the first distal bevel gear 170 of the drive transfer assembly160 (FIG. 15). Rotation of the first spur gear 174, as described above,causes rotation of the primary and secondary drive gears 192 a, 192 b.The latch housing 186 is configured such that a portion of the secondarydrive gear 192 b is exposed. As will be described in further detailbelow, when the loading unit 200 is secured to the latch housing 186 ofthe distal body portion 104 of the adapter assembly 100, the secondarydrive gear 192 b engages a drive gear 238 (FIG. 20) of an actuationassembly 230 (FIG. 20) of the loading unit 200 to enable actuation ofthe loading unit 200.

With continued reference to FIG. 18, the rotation drive gear 194 engagesthe second spur gear 176 mounted on the second end 172 b of the seconddistal bevel gear 170 of the drive transfer assembly 160 (FIG. 15) andthe toothed surface 182 a of cylindrical housing 182. Rotation of thesecond spur gear 176, as described above, causes rotation of therotation drive gear 194 which causes the rotation of the cylindricalhousing 182 and the latch housing 186 and further causes rotation of theloading unit 200 secured to the latch housing 186.

As shown in FIG. 18, the primary drive gear 192 a of the drive gearassembly 192 and the first spur gear 174 for driving the primary drivegear 192, as well as the rotation drive gear 194 and the second spurgear 172 for driving the rotation drive gear 194 are disposed within thesame cross-sectional plane of the distal body portion 104. This compactdesign of the drive transfer assembly 160 and the drive assembly 190 andthe location of the power transmission within the articulation joint 105allows for a shortened length of the distal body portion 104. Theshortened length of the distal body portion 104 allows for increasedmanipulability of an end effector, e.g., the loading unit 200, during asurgical procedure.

As shown, the length of the distal body portion 104 is substantiallyequal to the diameter of the distal body portion 104. Alternatively, thelength of the distal body portion 104 may be less than the diameter ofthe distal body portion 104. In this manner, the secondary drive gear192 b of the drive gear assembly 192 is disposed within one diameterlength of the articulation joint 105. For example, if the diameter ofthe distal body portion 104 is fifteen millimeters (15 mm), the distancebetween the pivot pin 107 of the articulation joint 105 and the primarydrive gear 192 a is less than fifteen millimeters (15 mm). Inembodiments, the distance between the pivot pin 107 and the secondarydrive gear 192 b is between five millimeters (5 mm) and thirtymillimeters (30 mm), and more specifically, between ten millimeters (10mm) and twenty millimeters (20 mm).

The loading unit 200 and the cartridge assembly 300 will be describedwith reference to FIGS. 19-31. The loading unit 200 includes a carrier210, an anvil assembly 220, an actuation assembly 230, and a lockingmechanism 250. The carrier 210 and an anvil member 222 of the anvilassembly 220 are pinned together by a pair of pins 222 a, 222 b and aremovable between open (FIG. 4) and closed (FIG. 19) positions. The anvilmember 222 is biased to the open position by a leaf spring 204. Thecarrier 210 defines a longitudinal recess 211 for operably supportingthe actuation assembly 230 and selectively receiving the cartridgeassembly 300. Optionally, an insert or pad 206 is received with thelongitudinal recess 211 of the carrier 210 between the carrier 210 andthe cartridge assembly 300 to reduce the friction between a drive beam240 of the actuation assembly 230 and the carrier 210 during operationof the loading unit 200. An electrical contact member 208 is supportedin the carrier 210 and is in electrical communication with the handleassembly 10 (FIG. 1) through the adapter assembly 100 (FIG. 1) when theloading unit 200 is secured to the adapter assembly 100.

With particular reference now to FIGS. 21-23, a proximal end of thecarrier 210 is configured to selectively secure loading unit 200 toadapter assembly 100. Specifically, the carrier 210 includes anextension 212 that engages the latch housing 186 of adapter assembly100. The extension 212 defines a cutout 213 for receiving the tongue 186a of the latch housing 186 of the adapter assembly 100. The extension212 further defines a pair of notches 213 for receiving the lips 186 bof the latch housing 186 of the adapter assembly 100. The extension 212still further defines a recess 215 (FIG. 23) for receiving the distalend 188 b of the latch member 188 of the latch mechanism 180 of theadapter assembly 100 when the loading unit 200 is engaged with theadapter assembly 100 for frictionally securing the loading unit 200 tothe adapter assembly 100. The extension 212 also defines a pair oflongitudinal bores 217 (FIG. 29) for operably receiving locking members252 and biasing members 254 of a locking mechanism 250, as will bedescribed below.

With particular reference to FIGS. 21 and 22, the loading unit 200 issecured to the adapter assembly 100 by aligning the tongue 186 a of thelatch housing 186 of the adapter assembly 100 with the cutout 213 of thecarrier 210 of the loading unit 200 and the lips 186 b of the latchhousing 186 of the adapter assembly 100 with the notches 215 of thecarrier 210 of the loading unit 200 and moving the loading unit 200relative to the adapter assembly 100. The tongue 186 a and lips 186 b ofthe latch housing 186 are received within the respective cutout 213 andnotches 215 until the distal end 188 b of the latch member 188 of theadapter assembly 100 aligns with and is subsequently received within therecess 215 in the carrier 210 of the loading unit 200. The distal end188 b of the latch member 188 may be conical, as shown in FIG. 21, tofacilitate retraction of the latch member 188 within the secondlongitudinal opening 185 b of the latch housing 186 against the bias ofbiasing member 189 (FIG. 23) as the tongue 186 a and lips 186 b of thelatch housing 186 are received within the respective cutout 213 andnotches 215 in the carrier 210 of the loading unit 200.

The receipt of the distal end 188 b of the latch member 188 in therecess 215 of the carrier 210 of the loading unit 200 frictionallysecures the loading unit 200 with the adapter assembly 100. The receiptof the distal end 188 b of the latch member 188 in the recess 215 mayproduce a tactile and/or audible feedback to the user indicating thatthe loading unit 200 is securely attached to the adapter assembly 100.Prior to the cartridge assembly 300 (FIG. 30) being received within thelongitudinal recess 211 of the carrier 210 of the loading unit 200and/or once the cartridge assembly 300 has been removed from the carrier210, the loading unit 200 may be separated from the adapter assembly 100by overcoming the friction force provided by the latch member 188 of thelatch mechanism 180.

With continued reference to FIG. 20-23, the actuation assembly 230 ofthe loading unit 200 includes a lead screw 232 rotatably supportedwithin the carrier 210 by a bearing assembly 234 and a bearing member236. A drive gear 238 is supported on a proximal end 232 a of the drivescrew 232 between the bearing assembly 234 and the bearing member 236.The drive gear 238 engages the secondary drive gear 192 b (FIG. 21) ofthe adapter assembly 100 when the loading unit 200 is secured to theadapter assembly 100 and functions to transfer the rotational motionfrom the secondary drive gear 192 b to the drive screw 232 of theloading unit 200. A distal end 232 b of the drive screw 232 is threadedand supports a drive beam 240 thereon.

Turning briefly to FIGS. 24-26, the drive beam 240 of the loading unit200 includes a retention portion 242 and a vertical support portion 244.The retention portion 242 of the drive beam 240 is configured forthreaded engagement with the threaded distal end 232 b of the drivescrew 232 (FIG. 20). A flange 242 a formed on the retention portion 242of the drive beam 240 maintains the drive beam 240 in a verticalorientation relative to the carrier 210 (FIG. 20) and the staplecartridge 300 (FIG. 19). The vertical support portion 244 of the drivebeam 240 includes a cam member 246 a and a knife member 246 b. The cammember 246 a is formed on a free end of the vertical support portion 244of the drive beam 240 and is configured for selective engagement with aledge 224 (FIG. 23) of the anvil member 222 of the anvil assembly 220.As will be described in further detail below, engagement of the cammember 246 a of the drive beam 240 with the ledge 224 of the anvilmember 222 causes anvil member 222 to move from the open position (FIG.4) to the closed position (FIG. 19) and maintains the anvil member 222in the closed position. The knife member 246 b of the vertical supportportion 244 of the drive beam 240 is configured to cut the tissue (notshown) clamped between the cartridge assembly 300 (FIG. 19) and theanvil member 222 (FIG. 19) during actuation of the loading unit 200.

In embodiments, and as shown, the drive beam 240 is formed of metal,e.g., stainless steel, or other suitable material. The retention portion242 and the cam member 246 a of the drive beam 240 each include a moldedinsert 243, 247, respectively, formed of plastic, e.g., peek, or othersuitable material. The molded inserts 243, 247 are co-molded with therespective retention portion 242 and the cam member 246 a of the drivebeam 240. The molded insert 243 includes wings 243 a formed on uppersurfaces of the flange 242 a of the retention portion 242 on either sideof the retention portion 242. The wings 243 a operate to reduce thefriction between the drive member 240 and the carrier 210 of the loadingunit 200, thereby reducing the input torque necessary to advance thedrive beam 240 through the carrier 210. Similarly, the molded insert 247includes wings 247 a on an undersurface of the cam member 246 a oneither side of the vertical support portion 244 of the drive beam 240.The wings 247 a reduce friction between the drive beam 240 and the anvilmember 222, thereby reducing the input torque necessary to advance thedrive beam 240 through the carrier 210 of the loading unit 200. Thestainless steel portions of the drive member 240 provide sufficientstrength to support the loads required to clamp and fire a plurality ofstaples (not shown).

As shown in FIG. 25, in addition to the threads provided in the moldedinsert 243, the retention portion 242 of the drive beam 240 is alsoprovided with threads. The threads of the retention portion 242correspond to the threads of the molded insert 243 and operate toreinforce the threads of the molded insert. In this manner, the threadsof the retention portion 242 strengthen the engagement between the drivebeam 240 and the lead screw 232, thereby reducing the likelihood offailure during operation of the loading unit 200.

Turning to FIG. 26, the molded insert 243 of the drive beam 240 isprovided with anti-rotation features 243 b. The anti-rotation features243 a extends through flange 242 a of retention portion 242 to fixmolded insert 243 within retention portion 242 and prevent rotation ofthe molded insert 243 during advancement and retraction of the drivebeam 240. With particular reference now to FIG. 23, the loading unit 200may be provided to the surgeon with the anvil member 222 of the anvilassembly 200 in the open position (FIG. 4) or in the closed position(FIG. 19). When provided to the surgeon in the closed position,following attachment of the loading unit 200 to the adapter assembly100, the loading unit 200 is moved the open position to permit loadingof the cartridge assembly 300 within the longitudinal recess 211 of thecarrier 210. As noted above, the anvil member 222 of the loading unit ismaintained in the closed position through engagement of the cam member246 a of the drive member 240 with the ledge 224 of the anvil member222. Accordingly, to move the loading unit 200 to the open position thedrive beam 240 is moved proximally, i.e., retracted, as indicated byarrow “A” in FIG. 23, to disengage the cam member 246 a of the drivebeam 240 from the ledge 224 of the anvil member 222.

As described above, the drive beam 240 is translated longitudinallyrelative to the drive screw 232 by rotating the first drive shaft 116,which rotates the first proximal bevel gear 162, which rotates the firsthorizontal bevel gear 166, which rotates the first distal bevel gear170, which rotates of the first spur gear 174, which rotates the primarydrive gear 192 a thereby rotating the secondary drive gear 192 b, whichrotates the drive gear 238 of the loading unit 200, which rotates thedrive screw 232 to move the drive beam 240. Rotation of the first driveshaft 116 in a first direction causes the drive beam 240 to move in theproximal direction and rotation of the first drive shaft 116 in thesecond direction causes the drive beam 240 to move in a distaldirection, i.e., advance, as indicated by arrow “B” in FIG. 23.

Proximal movement of the drive beam 240 causes the cam member 246 a ofthe drive beam 240 to disengage from the ledge 224 of the anvil member222. Once the cam member 246 a of the drive beam disengages the anvilmember 222, the leaf spring 204 biases the anvil member 222 to the openposition. Once open, the cartridge assembly 300 is received within thelongitudinal passage 211 of the carrier 210 of the loading unit 200.

The loading unit 200 may then be received through an access port (notshown) and positioned about tissue to be stapled (not shown) in atraditional manner. At any point during the stapling procedure, asdescribed in detail above, the loading unit 200 may be articulatedrelative to the proximal body portion 102 of the adapter assembly 100and/or the loading unit 200 may be rotated about the longitudinal axis“x” of the adapter assembly 100 for positioning the loading unit 200.

With reference still to FIG. 23, once tissue to be stapled (not shown)is received between the anvil member 222 of the anvil assembly 220 andthe cartridge member 310 of the cartridge assembly 300, rotation of thefirst drive shaft 116 of the adapter assembly 100 in a second directioncauses the drive beam 240 of the loading unit 200 to move distally. Asthe drive beam 240 moves distally, the cam member 246 a of the drivebeam 240 engages the ledge 224 of the anvil member 220 to cause theclosing of anvil member 220. Continued distal movement of the drive beam240 effects movement of an actuation sled 330 of the cartridge assembly300 into pusher members 332 to cause the stapling of tissue (not shown).As the drive member 240 is moved distally, the knife member 246 bengages and cuts the stapled tissue (not shown). Once the tissue (notshown) is stapled and cut, the drive beam 240 is refracted throughrotation of the first drive shaft 116 in the first direction, asdescribed above.

The loading unit 200 may then be removed from the patient and the spentcartridge assembly 300 may be separated or unloaded from the carrier210. Once the spent cartridge assembly 300 is separated from the carrier210, the loading unit 200 may be separated from the adapter assembly 100and discarded. Alternatively, a new cartridge assembly 300 may beattached to or loaded into the loading unit 200 to permit reuse of theloading unit 200.

With reference now to FIGS. 27-31, as noted above, the loading unit 200includes a locking mechanism 250 for preventing separation of theloading unit 200 from the adapter assembly 100 when the cartridgeassembly 300 is secured within the loading unit 200. The lockingmechanism 250 includes a pair of locking member 252 and a pair ofbiasing members, i.e., springs 254, received within the locking members252. Pins 256 extend through slots 253 in the locking members 252 toretain the biasing members 254 about the locking members 252 and tosupport the locking members 252 within the longitudinal bores 217 of theextension 212 of the carrier 210. The locking members 252 include distalprojections 252 a that extend into the longitudinal recess 211 of thecarrier 210 and engage a proximal end 300 a of the cartridge assembly300 when the cartridge assembly 300 is operably secured to the carrier210. As shown in FIG. 31, a proximal end of a cartridge body 310 of thecartridge assembly 300 includes a pair of notches 313 for receiving thedistal projections 252 a of the locking members 252.

With particular reference now to FIG. 27, when the locking mechanism 250is in a first position, i.e., prior to the cartridge assembly 300 beingreceived within the longitudinal recess 211 of the carrier 210 of theloading unit 200, the locking members 252 are in a distal-most position.When in the distal-most position, the loading unit 200 is separable fromthe adapter assembly 100, as described above.

Turning to FIGS. 28 and 29, when the cartridge assembly 300 is receivedwithin the longitudinal recess 211 of the carrier 210, the proximal end300 a of the cartridge assembly 300 engages the distal projections 252 aof the locking members 252 causing the locking members 252 to move in aproximal direction, as indicated by arrow “C” in FIG. 28, and into thebores 185 c of the latch housing 186 of the adapter assembly 100.Receipt of the locking member 252 within the bores 185 c of the latchhousing 186 secure the loading unit 200 to the adapter assembly 100 andprevent the loading unit 200 from accidently detaching from the adapterassembly 100 during operation of the loading unit 200.

Turning briefly to FIGS. 30 and 31, the cartridge assembly 300 includesthe cartridge body 310 and a cartridge housing 320. The cartridgehousing 320 securely receives the cartridge body 310 and defines alongitudinal slot 321 for receiving the drive screw 232 of the actuationassembly 230 of the loading unit 200 therethrough. As noted above, thecartridge assembly 300 further includes the actuation sled 330 and thepusher members 332. For a detailed description of an exemplary cartridgeassembly, please refer to commonly owned U.S. patent application Ser.No. 14/257,063 filed Apr. 21, 2014, entitled “Adapter Assembly withGimbal for Interconnecting Electromechanical Surgical Devices andSurgical Loading Units, and Surgical Systems Thereof,” the entirecontent of which is incorporated herein by reference in its entirety.

With reference now to FIGS. 32-40, an adapter assembly in accordancewith another embodiment of the present disclosure, shown generally asadapter assembly 400, and a loading unit according to another embodimentof the present disclosure, shown generally as loading unit 500, areconfigured for selective connection to the handle assembly 10 (FIG. 1).The adapter assembly 400 is configured for selective connection with thehandle assembly 10, and, the loading unit 500 is configured forselective connection with the adapter assembly 400. As will be shown anddescribed in detail below, the loading unit 500 is a single use loadingunit configured to fixedly receive a cartridge assembly 600; however, itis envisioned that the loading unit 500 may be modified to receive areplaceable cartridge assembly (not shown).

The adapter assembly 400, the loading unit 500 and the cartridgeassembly 600 operate to staple and cut tissue. The adapter assembly 400and the loading unit 500 are substantially similar to the adapterassembly 100 and the loading unit 200 described hereinabove, andtherefore, will only be described to the extent necessary to detail thedifferences therebetween.

With reference initially to FIG. 32, a proximal body portion 402 (only aproximal connector housing 406 shown) and a distal body portion 404 ofthe adapter assembly 400 are substantially the same as the proximal bodyportion 102 (FIG. 3) and the distal body portion 404 (FIG. 3),respectively, of the adapter assembly 100 (FIG. 3) describedhereinabove. Accordingly, the proximal and distal body portions 402, 404will only be described in detail to the extent necessary to distinguishthe differences therebetween.

With reference now to FIGS. 32 and 33, a distal connector housing 408 ofthe distal body portion 404 is pivotally connected relative to theproximal connector housing 406 of the proximal body portion 402 by apivot member 450. The adapter assembly 400 includes a drive transferassembly 460 operably supported within proximal and distal connectorhousings 406, 408, and a drive assembly 490 operably supported withinand extending through a cylindrical housing 482, support plate 484, andlatch housing 486 of distal body portion 404. The support plate 484 issecured to the distal connector housing 408 by a pair of screws 483 aand the latch housing 486 is secured to the cylindrical housing 482 by apair of screws 483 b. Alternatively, the support plate 484 and distalconnector housing 408 and/or the latch housing and the cylindricalhousing 482 may be secured to each other in any suitable manner, e.g.,threading, friction fit, mechanical fasteners.

With particular reference to FIG. 33, briefly, the drive transferassembly 460 includes first and second proximal bevel gears 462, 464,first and second horizontal bevel gears 466, 468, and first and seconddistal bevel gears 470, 472. The drive gear assembly 490 includes aprimary drive gear 492 a and a secondary drive gear 492 b fixedlysecured relative to the primary drive gear 492 a, and a rotation drivegear (not shown). For a detailed description of the operation of thedrive transfer assembly 460 and drive gear assembly 490, please refer tothe drive transfer assembly 160 (FIG. 15) and the drive gear assembly190 (FIG. 15) of adapter assembly 100 described hereinabove.

With continued reference to FIGS. 32 and 33, the latch housing 486 ofthe distal body portion 404 of the adapter assembly 400 is configuredfor selective connection with the loading unit 500 (FIG. 32). The latchhousing 486 defines a first longitudinal opening 485 a for receiving abearing assembly 487 and a second longitudinal opening 485 b foroperably receiving a latch mechanism 480. The bearing assembly 487rotatably supports the drive gear assembly 490 and the latch mechanism480 selectively secures the loading unit 500 to the distal body portion404 of the adapter assembly 400.

The latch mechanism 480 includes a latch member 488, a biasing member489, and a cap member 489 a for retaining the latch member 488 and thebiasing member 489 within the second longitudinal opening 485 b. Thelatch member 488 includes a proximal portion 488 a configured foroperable engagement by a user and a distal portion 488 b configured tobe selectively received within a recess 515 (FIG. 34) defined in anextension 512 of a carrier 510 of loading unit 500. The latch mechanism480 operates to selective secure the loading unit 500 to the distal bodyportion 404 of the adapter assembly 400. Specifically, the biasingmember 489 of the latch mechanism 480 biases the distal portion 488 b ofthe latch member 488 into the recess 515 formed in the extension 512 ofthe carrier 510 of loading unit 500 when the loading unit 500 is engagedwith the latch housing 486 of the adapter assembly 400 to prevent theloading unit 500 from disengaging from the latch housing 486 of theadapter assembly 400. Proximal movement of the latch member 488, againstthe bias of the biasing member 489, through engagement of the proximalportion 488 a of the latch member 488 retracts the distal portion 488 bof the latch member 488 from within the recess 515 in the extension 512of the carrier 510 of the loading unit 500, thereby permitting theloading unit 500 to be separated from the adapter assembly 400 in thesame manner loading unit 200 is separated from adapter assembly 100,described hereinabove.

With reference now to FIG. 34, the loading unit 500 includes the carrier510, an anvil assembly 520, an actuation assembly 530, and a plungerassembly 550. A distal end of the carrier 510 of the loading unit 500defines a longitudinal recess 511 for receiving the staple cartridge600. The cartridge assembly 600 may be permanently affixed within thelongitudinal recess 511 of the carrier 510 such that the cartridgeassembly 600 cannot be replaced, i.e., for single use, or the cartridgeassembly 600 may be selectively secured with the longitudinal recess 511of the carrier 510 to permit replacement of the cartridge assembly 600,i.e., for multiple uses. The anvil assembly 520 includes an anvil member522 pivotally secured to the carrier 510 by a pair of pivot pins (notshown). The anvil member 522 includes a C-shaped frame portion 524. Aswill be described in further detail below, a proximal end 524 a ofC-shaped frame portion 524 is configured for operable engagement by adistal end 560 a (FIG. 35B) of a longitudinal body portion 560 of aplunger member 552 of the plunger assembly 550.

With continued reference to FIG. 34, the actuation assembly 530 includesthe drive screw 532 and a drive beam 540. With additional reference toFIGS. 35A and 35B, the plunger assembly 550 is operably mounted withinan extension 512 of the carrier 510 and includes a plunger member 552, aspring member 554, and an end cap 556. The plunger member 552 of theplunger assembly 550 is slidably disposed within the extension 512 ofthe carrier 510 of the loading unit 500 and is configured to bias theanvil member 522 of the anvil assembly 520 to an open position (FIG.40). Specifically, the plunger member 552 includes a cylindrical bodyportion 558 received within a longitudinal bore 517 formed in theextension 512 of the carrier 510. A distal end 554 b of the springmember 554 is received within a cylindrical recess 553 defined by thecylindrical body portion 558. The plunger member 552 and the springmember 554 are maintained within the longitudinal bore 517 of theextension 512 by the end cap 556. The end cap 556 may be secured to theextension 512 of the carrier 510 by friction fit, welding, adhesive,mechanical fasteners, or in any other suitable manner. Alternatively,the end cap 556 and the longitudinal bore 517 may be threaded or includea tab and slot arrangement for securing the end cap 556 to the extension512 of the carrier 512.

The plunger member 552 of the plunger assembly 550 is biased in a distaldirection by the spring member 554. Although shown in the form of atraditional coil spring, the spring member 554 may include any mechanismor material exhibiting elastic characteristics, e.g., pneumatic orhydraulic cylinder, rubber bumper. An elongate body portion 560 of theplunger member 552 is operably received within the longitudinal slot 319formed in the extension 512 of the carrier 510. A distal end 560 a ofthe elongate body portion 560 of the plunger member 552 engages theanvil member 522 of the anvil assembly 520 to bias the anvil assembly520 to the open position (FIG. 40).

With reference now to FIGS. 37 and 38, as described above with regardsto the loading unit 200, the loading unit 500 may be provided to theclinician in the closed position, the loading unit 500 may be closedprior to insertion into the body cavity (not shown) of a patient (notshown), or the loading unit 500 may be closed subsequent to positioningthe tissue to be stapled (not shown) between the cartridge assembly 600and the anvil member 522 of the anvil assembly 520. As the anvil member522 is pivoted to the closed position, the proximal end 524 a of theC-shaped frame 524 of the anvil member 522 engages the distal end 560 aof the elongated body portion 560 of the plunger member 552 of theplunger assembly 550. The anvil assembly 520 may be moved to the closedposition through advancement of the drive beam 540 of the actuationassembly 530 or through manual engagement of the anvil assembly 520 bythe clinician. Engagement of the plunger member 552 of the plungerassembly 550 by the anvil member 522 as the anvil member 522 of theanvil assembly 520 is pivoted to the closed position causes the plungermember 552 to move in the proximal direction, as indicated by arrow “D”.As plunger member 552 is moved proximally, i.e., retracted, springmember 554 of the plunger assembly 550 is compressed to provide a springbias against anvil member 522.

Turning now to FIGS. 39 and 40, whether the anvil assembly 520 was heldclosed manually by a clinician or closed through operation of the drivebeam 540 of the actuation assembly 530, release of the anvil assembly520 by the clinician or disengagement of the drive beam 540 the anvilmember 522 permits the anvil assembly 520 to move to the open position.The spring bias generated by compressing spring member 554 during theclosing of anvil assembly 520 acts on plunger member 552 to move theplunger member 552 in the distal direction, as indicated by arrow “E”.Engagement of the distal end 560 a of the elongated body portion 560 ofthe plunger member 552 with the proximal end 524 a of the C-shaped frame524 of the anvil member 522 to cause the pivoting of the anvil member522 to the open position.

Upon completion of a stapling procedure, the loading unit 500 may beseparated or unloaded from the adapter assembly 400 in the mannerdescribed above. Additional loading units may then be attached to theadapter assembly 400 for subsequent stapling procedures. As noted above,the loading unit 500 may be configured to receive a replaceablecartridge assembly (not shown) for permitting reuse of the loading unit500. The adapter assembly 400 may be separated from the handle assembly10 (FIG. 1) and discarded. Alternatively, the adapter assembly 400 maybe sterilized and reused.

Any of the components described herein may be fabricated from eithermetals, plastics, resins, composites or the like taking intoconsideration strength, durability, wearability, weight, resistance tocorrosion, ease of manufacturing, cost of manufacturing, and the like.

It will be understood that various modifications may be made to theembodiments of the presently disclosed adapter assemblies. Therefore,the above description should not be construed as limiting, but merely asexemplifications of embodiments. Those skilled in the art will envisionother modifications within the scope and spirit of the presentdisclosure.

What is claimed is:
 1. A surgical apparatus comprising: a proximal bodyportion; a distal body portion selectively articulable relative to theproximal body portion at an articulation joint and including a distalend configured for selective engagement with a loading unit, the distalbody portion defining a longitudinal axis and having a diameter and alength; and a first drive gear disposed within the distal body portion,wherein the length of the distal body portion is substantially the sameas the diameter of the distal body portion.
 2. The surgical apparatus ofclaim 1, wherein the drive gear is rotatable about the longitudinalaxis.
 3. The surgical apparatus of claim 1, further including a loadingunit selectively engageable with the distal end of the distal bodyportion, wherein the loading unit includes a second drive gearconfigured to engage the first drive gear when the loading unit issecured to the distal end of the distal body portion.
 4. The surgicalapparatus of claim 3, wherein the loading unit includes a drive screwand the second drive gear is disposed on a proximal end of the drivescrew.
 5. The surgical apparatus of claim 4, wherein the loading unitincludes a drive beam operably disposed on the drive screw and rotationof the drive screw causes advancement of the drive beam to staple andcut tissue.
 6. The surgical apparatus of claim 1, further including arotation gear disposed within the distal body portion for rotating thedistal end of the distal body portion about the longitudinal axis. 7.The surgical apparatus of claim 6, further including a drive transferassembly extending between the proximal and distal body portions, thedrive transfer assembly including first and second horizontal bevelgears disposed about the articulation joint, a first distal bevel gearoperably connected to the first horizontal bevel gear, and a seconddistal bevel gear operably connected the second bevel gear, the firstdistal bevel gear being connected to the first drive gear by a firstspur gear and the second distal bevel gear being connected to therotation gear by a second spur gear.
 8. The surgical apparatus of claim7, wherein the first and second spur gears, the rotation gear, and thedrive gear are disposed within the same cross-sectional plane.
 9. Thesurgical apparatus of claim 8, wherein the drive transfer assemblyfurther includes a first proximal bevel gear operably connected to thefirst horizontal bevel gear and a second proximal bevel gear operablyconnected to the second horizontal bevel gear.
 10. The surgicalapparatus of claim 9, further including first and second drive shaftsextending through the proximal body portion, the first drive shaftoperably connected to the first proximal bevel gear and the second driveshaft operably connected to the second proximal bevel gear.
 11. Thesurgical apparatus of claim 10, further including an articulationassembly disposed within the proximal body portion.
 12. The surgicalapparatus of claim 11, further including a pivot member disposed withinthe articulation joint, wherein the pivot member is fixedly secured tothe distal body portion and pivotally secured to the proximal bodyportion.
 13. The surgical apparatus of claim 12, wherein thearticulation assembly includes a flexible band received about the pivotmember.
 14. The surgical apparatus of claim 13, wherein the flexibleband is operably connected to a third drive shaft extending through theproximal body portion.
 16. The surgical apparatus of claim 15, whereinrotation of the third drive shaft effectuates articulation of the distalbody portion relative to the proximal body portion.
 17. The surgicalapparatus of claim 1, further including a handle assembly, wherein aproximal end of the proximal body portion is connected to the handleassembly.